The invention relates to a method and apparatus for processing thermoplastic yarn.
In processing thermoplastic yarn, it is frequently desirable to produce a yarn having increased bulk and cover, improved hand, etc. Several methods of processing yarn have been developed to produce a yarn with these qualities. Some of these processing methods produce a yarn plug such as stuffer box and fluid jet crimping techniques as known in the art. The yarn plug produced by crimping is subsequently broken up and extended to form crimped yarn by various methods such as air, friction, etc., coupled with a high speed takeoff means. The properties of the yarn such as denier, crimp and bulk are usually measured after the processed yarn is wound on packages. Since numerous conditions affecting the yarn can change involuntarily and without notice, the package of yarn is usually deniered to insure that it is within quality control limits. Thus adjustments to the process to bring the properties of the yarn within quality control limits necessarily cannot be made until at least one package of off denier or inferior quality yarn has been produced. It is not unusual to have a time lag of from 1 to 11/2 hours between the time when a package of off denier yarn has been produced and the time when it is detected by deniering and adjustments to the process are made. Thus at a production rate of four packages per hour per processing line, four to six off denier packages of yarn can be produced per processing line before the process is corrected.
In addition, deniering the packages of yarn generally wastes 90 meters of yarn per package plus it requires test equipment and personnel to perform that function. This in itself constitutes a significant expenditure over a period of time. Thus, considerable savings in time, money and material could be realized if a process were developed where deniering was not required to insure that the yarn produced was within quality control limits.
It is an object of the invention to provide a method and apparatus for processing thermoplastic yarn.
Another object of the invention is to provide a method and apparatus for processing thermoplastic yarn whereby deniering is not required to insure that the yarn produced is within quality control limits.